extremely lengthy closing, what do i do?

[Mark Elliott]

hello to everyone. i have a question regarding a closing that is taking far too long. i have a flip house here in western new york. i finished it and put it up for sale in late august 2014. signed a sales contract with the buyer on november 11th. since then, he, the buyer, has given me a long list of repairs he wanted done on the place, which i did, including replacing the roof, myself, in the middle of december. now, since the repairs have been completed, i thought the closing would take place, as scheduled, on january 5, 2015. that date is written right in the contract. since then, he has " waffled" around with his VA loan, switched to a different bank and type of loan, and, as you can imagine, postponed the closing multiple times. i have heard from my agent and attorney on rare occassions that they need " this" or " that" from me. the latest thing they wanted from me was a letter indicating when the roof was completed. they already know this. i re-read my contract. i have what i believe are numerous reasons to cancel the sale. every week i hear " it should happen next week." i have been hearing that since mid january and here it is late march. also, within the contract, i have found a clause that allows me to demand a closing within 7 days of any notice i give them. should i contact their attorney and envolk the 7 day closing or notify them of my intent to cancel the sale effective immediately if we do not get a closing soon? any advice would be greatly appreciated. thank you