********** invoicing

We have ordered Shoes from them 02/03/2020 (take note of date) I asked for an invoice before hand for payment & they said it will be sent with delivery. got the order, short of some stock, but got it. Invoice received was dated 30-12-2019 ( previous financial year) I have asked , for over 5 months, to rectify it. as I cannot pay & read in this invoice. they sent statements & the same invoice dated wrong, asking for payment, I explained again, it was promised to be rectified in a week. I have sent over 30 emails, which they all have received, no answer. I called today and they said another week. An associate called back and actually said nmo mid august, but he doesn't understand why its not paid yet ? HELLO read the 30 emails I sent. I tried to explain again and he did the old " im actually in a meeting " right. don't call clients when you're in a meeting perhaps? SO rude. WILL NEVER EVER SUPPORT THEM AGAIN. THIS IS *****. Will be reporting to the relevant authorities.