Declined a home loan due to mistake in billing.

Thank you Telkom because of you I am getting declined for a home loan. last year Febuary I canceled my Telkom ADSL line with you, I still paid for Febuary and for March, but you guys still invoiced me in April for a service that was cancelled and because I refused to pay that as it was an error and it reflects on my credit score the banks are refusing to give me a home loan.