>I assume that "reclamations" refers to complaints,

Amazingly, the Serbian expression for that sort of complaint (for a faulty product, bad service etc) is "reklamacija" :).

> "dilatoriness" to the fact that clients don't pay when they should, "cuts" to disconnecting the service for the client who doesn't pay.

>Otherwise, I find the English clear enough.

English seems to be like Italian or Spanish, easy to learn to a conversational level, and takes years to learn the tricks. I've learned English enough to read some Shakespeare when I was 11, and some more when I was 15 (so I read Joyce when I was 19) - but I still learn new things, and get regularly confused with the ways that whatever you say can be misunderstood :).