DELAYED & EXPIRED OTPs

Since early this morning OTPs to my phone have been so badly delayed that I've had to re-attempt transactions multiple times. When calling the Contact Center they gave me a number of supposed solutions involving my device such as rebooting, clearing my cache and even uninstalling my software. At no point did they offer to check their own systems which, in my opinion, Must be the problem as I now been struggling for over 5 hours and with multiple transactions - none of which have been successful. Everytime I eventually get the OTP and try to use it, it has already expired.