HMRC phone line

After being directed by the DWP to HMRC I have been on hold for two hours in an attempt to pay voluntary contributions for alleged gaps in my NI record, although I have contributed 42yrs full in my pensions record, by paying the gaps this will equate to 49yrs The DWP just direct me too HMRC, but failure by HMRC to answer the phone for over two hrs is a disgrace. Any ideas?

Same sorry story. I've tried tweeting them. Shall let you know if I get any success.

Hi Antony Pritchard,
We apologise for the current wait times on the phone lines, during this busy time of year we are receiving a high volume of calls, we are currently trying our best to reduce the long wait times, the quietest time of day for contacting the helpline is the first and last hour the lines are open, between 8-9am and 5-6pm. However if you are unable to call at these times, an alternative to contacting us via telephone is our customer webchat. Please find the link below:
Contact HMRC
Thank you.