AW510K, at key not working

Have tried everything I can find to get the at key to work on my Dell AW510K Mechanical Gaming Keyboard. Changing region/Language to no avail. Getting to the point of throwing it in the bin and getting a decent one. I have had to install the character map on my desktop which is not ideal. I am in the U.K. and have changed the keyboard language to U.K. English and back to American English but this has not worked? Any help please. I have followed a load of advice from the internet.

Thanks.

Mike