MTN Account over charged

MTN and norman and bisset attoeneys are charging me calls that i don't know anything about. so according to their statement means my account wont be payedup. For 2015 April:<br> 2015/03/27 Collection Commission (VAT Incl) R 57.00 R 4 660.86<br> 2015/04/06 Interest R 34.84 R 4 695.70<br> 2015/04/07 Telephone call made on *** R 19.38 R 4 715.08<br> 2015/04/08 Telephone call made on *** R 19.38 R 4 734.46<br> 2015/04/08 Telephone call made on *** R 19.38 R 4 753.84<br> 2015/04/13 Telephone call made on *** R 19.38 R 4 773.22<br> 2015/04/24 Interest To Date R 18.95 R 4 792.17<br> 2015/04/24 Outstanding Commission R 463.98 R 5 256.15<br> No one have made calls to me this month and i want them to reverse the amount charged above. and i want to challenge the fact that i am paying interest while this account is handed over. i have send them an email asking then to explain to me how the interest is being calculated? and they never rep****. they also because it was charged interest twice this month.and there is also commission money that i don't know why i am being charged that.please send me proof on your telephone statement/voice recordings that you really called me.