If you're a company wanting to do business with me, let me give you two little suggestions:
1) Hire people to make your phone calls who I can understand and who can understand me. Speaking to someone who's English is so heavily accented that I have to ask them to repeat things several times just frustrates me, and I'm sure it frustrates them as well. And it's equally unhelpful if I have to keep repeating myself to be understood.*
2) When I say I'm not interested, thank me and hang up. Do not keep talking. I do not enjoy hanging up on you, but I will.
*I have nothing against people who's first language is not English, but heavy accents are much more difficult to understand on the phone than face-to-face. All I'm suggesting is that when companies hire people to do phone sales, they should conduct a test run on the phone with the candidate to see if there's a problem with making themselves understood/understanding the other person.
End of rant. Thanks for listening.