Developer will not allow code review before payment

Hello,

I have asked my developer to put source code in bit pocket or any where of his choice so that code review can be carried out before payment. Seller said that it is not possible to do so without a deposit of the full cost of project in escrow.  

I have the following questions.

1. Does PPH have a facility where developer can put source codes for code review?

2. Is it OK for buyer to ask seller to make the source codes of a project available for a review before payment?

3. If Yes, what are the conditions for seller to make the source code available for review?

4. If No, how can buyer establish quality of work before payment.

5. Can buyer with hold payment of money into escrow because quality of work needed to be ascertained?

Please treat as very urgent. Work is held up because of a disagreement over the issues.

Thank you

chikezie_okike@hotmail.com

PPH project #2713852