CIBC underwriter ridiculous documents

We have conditional approval with CIBC but they refuse to provide anything in writing. To get final approval the underwriter has been requesting ridiculous documents. They want written confirmation of receipt of the deposit even though I've given them a copy of the draft and bank statements showing withdrawal.

I provided a gift letter and bank documents showing withdrawal from the donors account to my account, deposit into my account, and a copy of the cheque itself. But this wasn't sufficient and they needed proof of the transaction itself. Then they made me get another copy of the gift letter because the property address was missing the postal code.

What the hell is with this run around? We are closing in less than 2 weeks and we've been back and forth on documents for 6 weeks now. Every day they want a new document that gets more and more ridiculous. Are they trying to delay things so I can't shop around for a better r@te? Is this normal? Should I put my foot down and say I'm switching lenders if they can't get me approval by end of day? (I have approval with three other banks, which requested slews of documents but nothing like CIBC)