Home Services at The Home Depot

My husband is deployed to Afghanistan. I had Home Depot do an estimate on a roofing, siding and gutter job on my house. I had to use a POA contract to open the loan. They said they don't accept POA for a Home Depot credit card and was instead steered towards a Project Loan to complete the process. I was approved for 20k, with the estimate of the job being a total of around 24k, with the agreement that I pay the outstanding balance at the completion of the job. I got my card in the mail and was then told by financial that they couldn't bill the card for any of the work until I activated the card, which I tried to do, only to be told that they don't accept POA for a project loan either and they closed my account on the spot. The work had already started. The roof was on and the siding job had started. So I called financial again. In the meantime I went to the store and was put on the phone with someone who helped me by contacting the COO and got the loan pushed through. They billed the siding and gutters, but not the roof yet, so I took what money I had and put it towards the balance to pay it down so there was enough room on the card for the roof to be billed. I'm now being told I don't have a revolving line of credit and they are trying to hold me responsible for the entire amount of the roof out of pocket, which is $8200. No one told me this wasn't a revolving line of credit and I'm not trying to reneg on the debt, I just want it put on the card so that I can make reasonable payments on it until it's paid off. They are being VERY uncooperative and aren't trying to work with me at all. I feel that this is bad business practice on their part, and I will not EVER do business with them again. I did this as a surprise for my husband when he returned from Afghanistan for R&R and it has been nothing but a nightmare, and now I have to have HIM clean up this mess. I in no way hold the actual store responsible for this, my in store experience has always been very positive.