There is no such thing as a standard, good, cover letter
I want to apply for position as loyalty and customer relationship manager at a telecom company. While my experiences related only to sales could you help me in writing a good cover letter to apply for that position?
Thanks and best regards

So you must make sure first of all that your CV “answers” the requirements of the position as advertised.
The employers or recruiters will be looking at whether you have the qualifications to do the job, and the motivation to do it well. So make sure that is apparent from the CV too.
Why do you want to switch to loyalty and customer relationship management? Do you know what the job entails?
Read this module for more information about why you need a cover letter, what it should say and to see a downloadable example you can alter to suit your requirements. Follow this link;-
Maybe ask for a full job description. And then use the cover letter to highlight why you are the perfect fit, the candidate they are looking for.
And this is why there is no such thing as a standard cover letter. It’s about you, and the Company, and your relationship with them. Why they should consider your application.
So I hope you can see that I would need to know more about you and the company, and your reasons for applying, to be able to write an effective cover letter.
But I will give you some suggestions and make some assumptions. You will need to rewrite the letter with the appropriate facts and wording.
So don’t forget you must make your cover letter personal and tailored. Follow this link to see another downloadable example you can alter to suit your requirements.
I hope this is useful to you