A319
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Flight Crew Last 90 Days 175; Flight Crew Type 2334
ATC Issue All Types; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance
Procedure
Filed on the COMIX 2 STAR and slowed and level at FL220. We received slow to 250 and descend to 15;000 then handed off to next controller. We were slowed and just descending through FL218 and the new controller said climb back to FL230. When questioned he says climb to FL220. We received multiple delay turns and at one point were over 9;000 FT high on the profile for the COMIX; then cleared to LEJEN. We were never cleared to descend via the COMIX 2. Next controller seemed to think we were cleared in some form on the COMIX; but we informed him negative we were not. So we were turned on a high wide downwind and slowed to 210. We get descended to 7000; 6000; and finally 5000 on the downwind and well past the field. We were then turned direct VYDDA and descend to 4000; cleared for the RNAV. We were then re-cleared for the approach but from a 240 heading and 4000. The distance from VYDDA was 5-7 miles still. When descending out of 4500 ft ATC advised us Low Altitude Alert and told us to climb to 5000. As we were climbing through 4800 he re-cleared us for the approach at 4000. We descended to 4000 and continued to VYDDA. We received no warnings from the aircraft of any terrain issues whatsoever. So my First Officer questioned ATC what that was all about. ATC replies that he cleared us for the approach too early. We then got handed off to Tower and continued the approach to landing.
[Report narrative contained no additional information]
A320 flight crew reported receiving a low altitude alert on arrival into SAN after descending to ATC cleared altitude.