Trouble with new Dell pro wireless keyboard KM5221W

I have worked with desktop and mainfrain computer right from the very early days (late 1960's) to my retirement some time ago). Of all the problems I came across I was nearly always able to cfind a sulution. Now I have found a problem that has completely beaten me.

Yesterday I received my new Dell ec24250 complete with Sell Pro keyboard and Mouse (KM2221W). I maged to set up all the software workin, all my peripherals indtalled and the 100 accounts logged into, but!!!!!

I cannot close the battery cover on the rear of the keybord.

No matter what I do the cover just drops off as soon as I turn the keyboard up the correct way.

Please help a poor old codger with very bad eyesight.