If what you buy isn't right, here's how to handle it

Consumer complaints come in many forms. They may involve a product (a toaster that doesn't work), a service (carpet cleaners that leave your carpet spotted), or a hassle over a rent deposit refund. Outside the community, the No. 1 complaint involves mail-order operations. Within the community, automobile service leads the parade with 36 percent of all complaints. Your action in resolving a complaint will depend on type and location.

First, locally:

If you are dissatisfied with a product or service from a local firm or government agency, contact the firm first. If you fail to get the attention of the store manager or agency contact, go right to the top. Present your case to the president of the company or agency head in a letter or in person.

How you present your case will likely affect your success. Copies of bills, previous complaint letters, and summaries of talks with anyone involved will help to document your case. If you follow through to a media action line or small claims court, you will need evidence. Routinely keep records of consumer transactions -- all sales slips, warranties, dates and problems with service, and anything else that bears on your case.

If you get nowhere with the company, you should check these alternatives:

* Your local Better Business Bureau (BBB) may offer consumer arbitration. If your case is one involving a member, you can ask for a hearing. The BBB will attempt to mediate informally first and, if that fails, will follow through with arbitration at minimum or no cost to you.

* Appeal to one of the local media action lines. Most metropolitan newpapers maintain investigators or trouble-shooters as a reader service for the resolution of both local complaints and problems with mail-order firms.

* Small-claims court can be a last resort. Ask the court itself for help in filing and preparing your case. An attorney is not usually required.

A complaint about something you bought by mail can be more difficult. Attempt to work out the problem with the supplier first -- going to the president if a first contact fails. If those actions fail, consider the following:

* The Direct Mail Marketing Association, 6 East 43rd Street, New York, N.Y. 10017, will sometimes mediate or offer to help settle mail-order disputes when presented with adequate facts.

* Your state attorney general's office maintains regular contact with many mail suppliers. If your case appears justified, the attorney general may get on the phone and settle the problem quickly.

* Newspaper action-line columnists may also take up your case when fully documented. The usual action is for a reporter to contact the mail-order supplier to present the case. Numerous complaints are resolved through the publicity associated with action-line follow-through.

* Cases that appear to involve fraud, as distinct from a misunderstanding or delay, can be brought to the attention of the postal inspector at the post office servicing the mail-order supplier.

* Numerous government agencies and departments of larger agencies could also take up your case. For more information on these plus the names and addresses of state attorneys general and other offices both state and federal, refer to "HELP -- The Indispensable Almanac of consumer Information 1980," a new editon published by Everett House, 113 avenue of the Americas, New York, N.Y. 10036, $8 .95 at bookstores or by mail (include $1 for postage and handling). "HELP" contains 75 packed pages on where and how to resolve complaints.