Scam emails won't stop

[Tafkam]

Hi, I wonder if anyone can advise me here.
I have a normal exemail email address which I use most of the time, and it has the scam filter on it, but I also have a gmail account that I use for some things. For months now I've been getting these unsolicited fortnightly emails to the gmail account from a mob called Vet Products Direct, from whom I have never purchased anything, nor have I subscribed to anything from there. After a few of these emails I did the "unsubscribe" thing, to no avail, and did it again about 4 subsequent times. Eventually I rang the number on the bottom of the email and got the legitimate business, who say they don't have me subscribed to anything. I told them about the constant emails and was told she'd "look into it", and still they come. I rang again a couple of weeks later and was told the same things. I've tried "marking as junk" in Thunderbird but for some reason they still get through, even thought the "sender" is always the same; newsletter@vetproductsdirect.com
Other things I "mark as junk" are successfully dealt with, but not this one. My last resort is to get rid of that email address but that would be quite inconvenient. Any help appreciated.

[Mixer]

Tafkam, in Thunderbird /Tools use Message filters to create a rule that all email FROM vetproducts.com goes directly to trash.This will not stop them, but at least they go directly to the bin.
PS...Also would advise not to follow any links from any unknown source.
Clicking on any link can let scammers and spammers know that they have a fish, or worse can lead you to download something bad.

[Dazzled]

+1 for Mixer, but I'd go further - all messages containing that URL, whoever the sender, will be junked. See http://kb.mozillazine.org/Junk_Mail_Controls

[jokiin]

if the problem emails are to your Gmail account then I would be inclined to set a rule there, Gmail has good spam filtering available

[Tafkam]

Thanks guys, have set a filter and will see how it goes.