When you need me, call me-what is wrong with that?
Nothing at all.
To call.............to shout
To give me a call..............to phone
To call on...............to visit
The problem is the use of call. First of all, older people would use it in a slightly different way to younger people. Secondly, it is not clear when you say call me
, if you mean shout or phone.
Example: 1. I'm going to the other room. Call me
when dinner is ready.
Example: 2. I'll be at home this evening. Give me a call
, if you want to go out for a beer.
I'm not telling you that you are wrong. I'm showing problems that occur when using English. In the second example call me could also be used.