unfairly listed at the credit beaurau

I was contacted by summer mobile in June/July 2014 regarding a cellphone contract which I took in good faith.I cancelled the contract 4 days later and was told everything was sorted.Just to find in October2014 ,whilst applying for a home loan,that mtn blacklisted me with a judgement against my name.since then I have been in contact with summer mobile who on their turn was incontact with mtn'legal department.up to date I have handed over to Norton and associates who have been threatening me wirh court summonses none the less.Im mrs Ve Rusten,***,tel.no.***.would you please help me to clear my name and get a solution to this problem Im in please.Thank you very much.