Are you burying your head in the sand?
If your business deferred paying VAT between March and June 2020 and have not yet paid the amount owing or set up a payment scheme with HMRC you only have until 21 June 2021 to arrange a payment scheme with them.
This is the final opportunity to spread payments with no interest or penalty being charged. The scheme can be set up online through this HMRC VAT Deferral link so you don't have to call HMRC during working hours. The link gives you plenty of information to assess whether you are eligible for the scheme and how to apply.
It is very quick and easy to set up so, whilst it might seem daunting and time consuming, once you sit down to do it it is surprisingly straightforward. You will need your bank details so payments can be taken each month by direct debit.
Time to Pay
If you are not able to make regular payments then you must call HMRC to set up a Time to Pay arrangement with them. You will be able to agree a more manageable amount and a longer time period although there will be interest due on the outstanding amount. This link to HMRC's Difficulty Paying information will provide you with the contact details you need.
You can arrange to pay other taxes which you have not been able to pay when you ring them.