The answer to your question will lie in the documents you signed with your application. There are lenders who will charge for the credit report up front and if the appraisal has been done you likely owe for that too. Beyond that is anyoneâ€™s guess and you are subject to the agreements you signed with the lender and their willingness to enforce them.
My question for you is, if you cancel are you prepared to start over with another lender? You say the seller will not extend, which may be their right, but then they are back on the market looking for another buyer with a failed sale.
I would suggest you raise heck with the lender, any supervisor or manager involved and let them know you intend to go public with your dissatisfaction on this and many other public sites. Often bad reviews will get a businessâ€™s attention and as long as you did your part in getting your documentation to them in a timely manner, it shouldn't be your fault. It sounds like you have made a good faith effort to obtain financing.
Phil DeSimone / Realtor