The seller is also the builder. We signed the purchase agreement and worked with the builder on agreed upon finishings of the house. Builder started to cheap out, we complained, they offered us in writing a full refund of deposit and upgrades paid to date. We accepted which would be a binding contract (offer - acceptance). They returned back with an approval BUT included other costs we would have to pay - which was not in the offer acceptance letter. They have my deposit and upgrades I agreed to and already paid for. They are ignoring all my calls. What other damages can I demand if this goes to court?