Not Fulfilling guarantee

This company guarantee their work on our Anvil oven repair for 6 months. After three months of our oven breaking down, i sms and called them and they kept on promising to come the next day. This has been going on for one month. So frustrating. ignoring what's app messages which you can see have been read.<br> Now they say we owe money. Isn't it funny that we have not been called once or even received an email/fax if we owed money since November. Or that in the begging of us saying that we having a problem with our oven that they would tell us we owe money and fax/email the invoice and say we can't come out until the invoice is paid. We have two invoices and both are paid.<br> I have checked with Anvil and with BCE and they are not preferred suppliers which they say they are. They are not linked at all!!