If you want to make a strong complain, what are the possible expressions would you write?
This approach to complaints letter-writing is effective for private consumers and for business-to-business customers who seek positive outcomes from writing letters of complaint. The principles apply to complaints emails and phone calls too, although letters remain generally the most reliable and effective way to complain, especially for serious complaints. Effective complaints letters (and any other way of complaining) should be: concise authoritative factual constructive friendly