you say it was passed onto you by your ex ? are the debts in your name / both of your names or his name. If the debt is in your name unfortunatley it is you that is responsible for it . debts in two peoples names makes you responsible for half which you should pay and pass over your ex's details for him to pay the other half. BE FIRM. companies dont like you doing this so explain you are prepared to pay half but not the full amount. If the debt is in his name it is not your responsibility and you should pass on contact details of your ex and forward letters appropriatley. you say the debt was passed on? how was this done ??
it may be worth speaking to a legal advisor if the debt is not soley in your name and seeing where you stand in being legally obliged to pay. I house shared with two other girls about a year ago and severn trent forwarded the whole bill to me which i refused to pay in full. I said that 3 names on the account meant i was obliged to pay a 1/3 of the bill - which i did - and then forwarded addresses for the other two so they could demand the other 2/3 .
Consolidation loans can help to pay off debts and give you one low monthly sum. Considating debt is a big issue at the moment and its worth seeing if some of your unpayable debt can be written off. I would definatly consider what debt is in your name only and those that are not should be halfed or forwared in whole to your ex - i would definatly seek legal aid if you dont feel you are responsible for the full amount