unpleasant text on my moble phone

You may not know that it IS a dodgy text until you have opened it and read it, so saying don't open it could be a bit too late. Opening a text won't let someone steal money from you, but clicking on any links in it could, or answering it to give them information like your bank details or other personal information. There are many places online advising you what to do if you get a text (or a phone call or email) that seems dodgy. Everyone should read at least one of these articles, and note where to send what they think could be scam messages.

Recognise - www.ncsc.gov.uk/collection/phishing-scams
Report - www.ncsc.gov.uk/collection/phishing-scams/report-scam-text-message
Avoid and report - www.gov.uk/report-suspicious-emails-websites-phishing
Recognise and report - www.consumer.ftc.gov/articles/how-recognize-and-report-spam-text-messages

I never open any unknown numbers

Kim19. What if the text was from your doctor or bank? Opening a text does not put you at any risk.

I have the numbers of my bank and surgery tberein.

In where? Do You mean in your phone or maybe your tablet?

A scammer can only see your phone numbers or account numbers in your device remotely if you allow them to, and that is what you could be allowing unawares if you clicked on a link in the text. Just reading the text doesn't do it, like just hearing someone ask you out loud what your bank A/C number is doesn't mean that you have given them the answer.

I had two texts from the Post Office telling me that a parcel I recently posted had been returned to "my local office". I need to follow the link and pay £1.99 to retrieve it.

Oh yes?
I did post a parcel to a charity but my postcode was on the parcel so I know Royal Mail would send it back to me if undelivered.

My phone is a primitive affair . All I did was go into the inbox and there was the text. Saying they know a lot about me.
Good for them! I deleted all messages.