MR time limit

I have received contradicting instructions from the DWP. I am requesting a MR and the letter I received with my award decision specifically states that I would need to request within one month of the date on my letter. It took three weeks for the letter to arrive leaving me 7 days for the request. On ringing the DWP to make the request the person I spoke to indicated the month would go from the date I called. I recorded the conversation. Going by the call I would have three weeks in which to provide a response. Which is correct; the letter that took three weeks to arrive or the call that I only made five days ago? Thank you.

Much obliged Gordon. I think this was what the guy on the other end of the phone was indicating. He was allowing four weeks for the information to get back to them (including postage). he then sent me a text confirming the request along with a message it could take up to ten weeks for me to receive a decision.