If the item is valuable/worthy enough to you, you should have ask the sender to send by courier/registered, instead of normal mail, and pay extra. 

Normal mail = no way to track. Their answer will be "lost in transit" 

Even if it is truly stuck in customs (TV Tuner may need SIRIM approval to bring in), you will never ever know unless they inform you. Why ? There is no tracking number. The customs may just throw aside and forgot all about it, until one fine day, they pick it up and willing to contact you. What if they open it and found the TV Tuner very nice ? Take home lor! Malaysia Boleh! 

if u have tracking number it will be good and can the search scope can be reduce. if u only provide name and address those ppl at custom section would have a problem because need to look for every record. can't be done fast so the better way ask sender to send it using ems or registered parcel.

u may try go to the custom office (unit bungkusan pos) and ask them for the record book. so u can have to check it manually. if there's no tracking number (cheapest) it will be under Letter Packet record book/file.

Near terminal LCCT...there's a Pusat Mel building there where the customs and pos malaysia people located under one roof 

If you did not receive a letter from pos malaysia+customs requesting you to clear your item then most likely is has not arrive here yet. 

You should get more info from your seller...post normal parcel by airmail or ground/surface mail? Air mail is by aeroplane and ground mail is by ship (sea) which usually takes 2-3 months to arrive depending on which country.  You should also be reminded that normal mail cannot be tracked but if your seller has kept a copy of the custom declaration form you could use the customs declaration form number for reference.  If not then it is virtually impossible to locate your stuff