You can't block just one number on a mobile, we've tried. However, we have found out who they are, Equidebt, a debt collection agency in Warwickshire. They were after us for a debt that was settled a long time ago - and they had the cheek to say it was in my name - it wasn't, it was my husbands, we soon put them right - on both counts. You were very unlucky to get all those phone calls without receiving a red debt notice, which is what we got sent out the day after we barred their number on the land line. Luckily, they haven't got either of our mobiles, so they couldn't ring them. Now when people ask for a number, we say no. Mobiles are for personal use only, home no is exdirectory and work numbers are out of bounds. If they want to contact us they can write. Tough luck if they don't like it, eh??
Hope this helps you, and if you'd like a number you can call them on, I can give it to you, or an address. Let me know. The number they ring on only has a recorded message, "There's no-one here to take your call at the moment, please try again later." And it then hangs up. No name of company, nothing. Very bad form. Do let me know if you want their in bound no and address, I'll be more than glad to give it to you.