Very suspicious ways of Comms

I would like to fully settled an outstanding amount that has been in Arrears. I speak to a consultant at the Call Centre. I get a settlement amount with a 25% Discount, THANK YOU for that. I request banking details via Email just stating Pay into FNB, Branch Name and Account number. No mention of who the Account Holders Name is? ***** - I then receive an SMS with the Same info but this time the amount is a R100-00 more than quoted. You know, with the amount of ****ms and ***** in this world i do not feel comfortable with how you expect people to settle and communicate with your company!! Dont you think having details on an Official Letter head stating ALL the relevant information is better than just slap dash SMS's or e mails? I for one dont know if i am dealing with reputable Business here??