Not the customer but a realitive that was at the party complained that the cake crumbled when it was cut, ok so as far as I know you need a really sharp knife to cut into fondant especially if it is in more than 1 layer. If this is true the actual customer did not call me and complain. I'm not sure if I should ask the one who actually paid for the cake if there was a problem. Could this have been avoided? The complainer has made comments on other occasions about my pricing and sarcasticly commented about this cake "how much was THAT $50.00?" no, it was $72.00 since I gave a family discount and it was my first time making this kind of cake, I charged for 30 servings because thats what she asked for but since I wanted to use the heart shaped pan a 10 inch would have been less than 30 servings so I went a size up, all in all with the lid I figured this would serve 55 (at least) and it's also a 3D cake- (someone tell me if I'm wrong) so in actuality I should have charged $220.00 ($4.00 per serving for 3D) for the cake at least!

I think your cake is beautiful and worth every cent you charged! Some people just need things to complain about. I wouldn't worry about it one more second!

I wouldn't worry about it. If the customer says something, you can address it then. And if the complainer ever asks for a cake, be sure to be booked on that date I've encountered people who act like that (my sister used to, back when I first started doing cakes, until she realized that mean people get no cake) and I think sometimes they act like that from jealousy.

..............sometimes they act like that from jealousy.............

That is exactly what I th ought when reading the OP's post.
This complainer has made not nice comments before....she has to be jealous.

So for future pricing on this sort of cake, is it safe to say that it serves 55 (the lid is one layer) earlene serving chart says a 12 inch heart serves 40? Is is considered 3D?

Well it might get me worried about my cakes. Are you sure that your cake didn't crumble a lot when cut? One time I made a new recipe and it did crumble a lot (I was at the party and I was mortified!) If you know your cake is fine, then I wouldn't worry about it at all. sounds like this person is jealous.

http://www.wilton.com/cakes/making-cakes/baking-wedding-cake-2-inch-pans.cfm

According to Wilton, a two layer 12 in heard serves 56 1x2x4 inch pieces. I can't tell if your cake is two layers on the bottom then another layer for the lid? If so, then I'd figure in another 28 servings (2x2x2) for the top. Making it a total of 84 servings. I'm not sure I'd call it a three 3D cake, because to me those are usually sculpted. I'm not sure I'd even charge any additional for the design, because even if it was three layers stacked on top of each other you'd have to decorate it, and there isn't anything that would go above and beyond to me. I take in consideration the decorations, but also factor decorating into the base cost as well.

If your fondant serving price is $4 then I would have figured that cake at $336 dollars. If you felt the need to do an up charge then I'd say something like $350, but I can't see really adding more for that design.

If your fondant serving price is $3 (since you mentioned $4 for sculpted) the I'd figure it at $252.

As far as the question about the cutting, yes there is a type of knife that cuts through fondant cakes well, and there is one that will cause the cake to fall about because it smooshes the cake down with the fondant, rather than cutting through the fondant.

If the person that got the cake hasn't said anything to you and the person that did comment is a known complainer, then I would probably leave it alone. You could always ask the person that bought the cake, but then you are opening up a can of worms there. As far as how to handle this other person, I would just ignore them. If you get riled up then they are more than likely to keep doing it. If you ignore them, they will get over it and move on to bother someone else.