Timeshare Collection Resolution?

While we were at our hotel we were informed that we would recieve free Disney tickets if we attended a resort presentation. It turnes out that it was for a timeshare. During the timeshare presentation they used high pressure tactics and I ultimatley caved in and signed for a timeshare with a 300.00 deposit. 2 days later after I got home I did not feel comfortable about after doing web searches and contacted the resort and told them I wish to cancel my timeshare and was informed I could not since I already made a deposit of 300.00. I informed the gentlemen that I would cancell my debit card that was setup for auto pay. IThe $300.00 is the only amount that they recieved from me. Never heard anything after that from the resort and thought it was over. 1 month ago after returning from my 5th combat deployment and reenlisting for INDEF service I decided that me and the family deserve to buy a house. After finding one and started the home buyer process the lender informed me that they could not help us due to the timeshare being in collections for 17,000. I usually only check equifax but I was informed that it is only being reported on Experian reporting agencies. Trying to know if anyone have any recommendations that could help me out regarding this. Just want to make the right decision so I could buy a house and get this collections off my report. Thanks