Confusion over Voluntary NIC DD

InkyB96

I've just had a letter from HMRC saying I need to pay an extra £226 to cover 3 months from Jan-April 23. However my direct debits were paid every month up until (and including) March and then for some reason just stopped, even though I have been paying voluntary contributions every month since July 2019. They haven't taken a DD for April, May or June this year. They say my DD will restart this July. If this is the case surely the £226 should be covering those missing months and not the ones I've already paid for. I can't see my pension forecast for last year yet and probably won't until October. There's no way I'd be able get through on the phone right now and don't even want to try! I'm thinking of waiting until I'm able to see my forecast and whether it's been sorted. Out of interest has anyone else had this kind of problem?