Bought electronic item from AliExpress. Pos Malaysia says my item held by customs.

Email from Pos:
Your item ELxxxxxxMY is currently held by Royal Malaysian Customs due to (high-value/import permit required/SST issue).
You have three options for Customs clearance:
1. Appoint Pos Malaysia (PMB) as your clearance agent.
2. Self-clear at: Pos Malaysia International Hub, Jalan KLIA S1, 64000 Sepang
3. Appoint your own Customs agent

I do have a few questions:
A) If I appoint Pos as my clearance agent, I just need to email (cspmih@pos.com.my) them my online purchase? After that, they will guide me with payment method? How long more to wait for delivery to my house? I search on internet and someone says this process take about 1 month.

B) For self clear, if I go to Pos KLIA myself, can this whole process be done in a day (or hours)? Can get my item on the same day? I need time-off from work for this. Is there anywhere else that I need to go besides Pos? Just need to show proof of online purchase to Pos? Where to park and enter Pos KLIA? I look at GMaps and still don't know the exact spot.

C) Any good, reliable and fast agent to recommend?

how long does it take for them to quote you the payment? they email you the instruction on how to pay? now, I get both email and whatsapp from the staff. still waiting for their quote.