MTN can't be bothered to obey the law

First MTN changes to this irritating system where they don’t send you an actual invoice, but rather a link to a portal that requires you to receive an OTP on your cellphone on MTN’s own network, yet this OTP never seems to arrive, so you have to phone their dismal call centre to get access to your own invoice. In October of last year they stopped even bothering to send out the invoice link. Despite numerous requests this has not be resolved. MTN, you are required by law to send me an invoice, monthly for the services for which you are billing me. Kindly comply with your legal obligations with immediate effect.