not understanding what's being said on phone...

It’s not your fault. It’s hard to understand some foreign accents. I would say I’m sorry but i can’t understand what you’re saying. Can you speak slowly and more clearly please. If need be, repeat back to them what they’ve said. If they make a thing of it, say it’s your accent it’s hard for me to understand you. I’ve had the same issue, They must realise what you mean…don’t be put off.

I just keep asking them to repeat everything very slowly. If it's something important I can go on doing this for ages.If it turns out to be nothing I hang up. It isn't just foreign accents either. There are quite a few British ones I have problems with. With the ones who rattle away ay 100 miles an hour I let them say several sentences before I ask them to repeat the whole lot. This usually encourages them to slow down.

I used to get this a lot when I worked in a library - people phoning for whatever reason, mumbling and gabbling at the same time. The effect was exacerbated - sometimes a lot - by any strong foreign accent. Especially when they were reeling off their long membership number at a mega-gabble!

I just used to ask them to slow down and speak clearly.
There would often obviously be eye-rolls on the other end - they evidently thought I must be exceedingly stupid - but that didn’t bother me.

Overseas call centres are a nightmare.
I recently had a Waitrose delivery problem on route to holiday.
A guy from Asia had to sort it out for me. Very well, I should say but what a palaver it all is.
I reckon they use C.C. as a ploy to stop too many, often nuisance, calls.