Standard bank holding my money without any valid reason

STD bank holding my declined transaction amount without any valid reason, I Ayanda Puleng Nohe, came to caltex fuel station on 04/03/2023 and had a transaction of R.518.77 which was declined for two to three times and they brought another machine for transaction, but I have received txt and on my banking app it indicates that amount has been deducted but it was declined on their machine, i came back to fuel station and they showed me in their batch report which indicates it is declined i spoken to STD bank over the phone it will take 24 to 48 hrs to reflect my transaction amount, but till now i've no amount received, i also went to bank but they was absolutely no help at all, as STD bank is holding my amount without any valid reason, I don't know when will i get my amount bank.

Regards Ayanda *** or ***