The email has a good structure, the author divided it into multiple paragraphs, in the first one he
explains the reason he is writing a complaint, in the second one he provides us with more details, but
in my opinion the language he uses is too difficult and uselessly complicated, I would suggest using
more simple and explanatory sentences, for example replace " due to certain issues on the recently
purchased cellphone " with "because my new cellphone did not work correctly" or "because I had
some problems with my new cellphone". I would also suggest replacing " I explained the issues I was
experienced with the cellphone " with " I explained the defects of the cellphone ", again I think that
the sentence is difficult to understand if not read multiple times.
I would also suggest to provide more detail on what the author wants the company to do in the last
paragrah, because he asks for " improvement of knowledge of employees " but doesn't specify what
kind of knowledge or information should they be taught.
At the end of the email, the author used "Sincerely" before the sign off, but Sincerely is usually used
when we know the name of the recipient, so I would suggest using "Yours faithfully" or "Yours truly"
instead.
There are some minor spelling mistakes like "writting" or "finaly" but overall the spelling and
grammar is okay.
Overall I think the author did a good job, he was polite and respectful all the time.