DTMF not working

[FabsSbg]

Hello folks,

I need your help and really would appreciate it, cause I'm desperate. 

I already asked Google and even looked at the second Page

My Problem is the following: I have to call a service number with an automatic call answer. The autmated system asks me to type my postal code, so that it knows where I'm from, so it could connect me to the nearest service station. When I type in the code it always says that it couldn't recognise the input and I shall control if the DTMF function is active on my phone. 

I just can't find any option to activate/deactivate such a function and the manuel also doesn't help me.

So please help me.

Greeting, F

[Thommo]

DTMF is the name given to the sound the dial pad makes when you tap a number - This should be under Settings then Sound then tick the box for Audible touch sounds near the bottom