Hi I'm trouble with SMD they don't want to give me my clearance letter

Hi I'm trouble with SMD they don't want to give me my clearance letter. I paid them for two years and I'm done paying them they keep on saying that I'm still owing them,when I check all my *** they we paid off and they sent me the paid off letter when I tell and send the proof of letters they don't come back to me even when,I call my calls are not answered. I'm stack in everything that I want to do can't open *** or take a loan because they always appear in every bank I go to even credit bureau when I check it shows that I'm not owing any one.can you please help me my life is stack this guy's are not okay they play with people life they don't care about people well being they only care when you're still paying them and when you're done they will come with stories after stories please,I need your help.