Collectors will often threaten you na ipapahiya ka.Can he do that? 

Revised Penal Code
Article 200 - Grave Scandal

The penalties of arresto mayor and public censure shall be imposed upon any person who shall offend against decency or good customs by any highly scandalous conduct not expressly falling within any other article of this Code.

 Oral defamation
 every defamatory imputation is presumed to be malicious, even if it be true; if no good intention and justifiable motive for making it is shown.

There is malice when the author of the imputation is prompted by personal ill-will or spite and speaks not in response to duty but merely to injure the reputation of the person who claims to have been defamed. Truth then is not a defense, unless it is shown that the matter charged as libelous was made with good motives and for justifiable ends.
(Abogadomo.com)