black listed

i am in the process of re mortgaging the FMH to pay her out but i am struggling to get the mortgage, because she never contributed to the debt after she left and i only paid what i could i have been black listed by association. the problem is the company who is black listing me would get all there debt paid. is there a way to get round this. the total debts was £700 a month and i was paying £550. the new mortgage would only be £370 and all the debts and settlement would be paid so i stand to gain £180 a month. what she has not realised that while she was living the high life she was also getting a bad credit rating. so when her new partner has to pay his wife £100k and they need a loan she wont get one and he is too old (63) toget one. maybe he will go back to his wife and leave her homeless then lets see who has the last laugh