Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Flight Crew Last 90 Days 90; Flight Crew Type 15700
Communication Breakdown
ATC Issue All Types; Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance
Human Factors
During descent we were given a clearance to depart ZZZ [VOR] on heading of 230 and descend to 8;000 feet.  Concurrently another Company aircraft; (Flight ABC) was given a descent clearance to cross 15 SW of ZZZ [VOR] at 8;000 feet.  They were subsequently given a frequency change.  At ZZZ [VOR] we took up a 230 heading. At approximately 15 SW of ZZZ [VOR] at 10;000 feet; the Controller asked if we were going to comply with the 8;000 feet restriction 15 SW of ZZZ [VOR].  I told him no; we were already at that point and we had not been given that clearance.  The Controller believed he had given us the same clearance as (Company Flight ABC).  He then gave me a frequency change and no further mention of the erroneous clearance.
On the ZZZZZ 5 Arrival into ZZZ [airport]; approaching ZZZ [VOR] ATC gave us 'Depart ZZZ [VOR] heading 230 descend and maintain 8;000 feet. We were complying with the clearance and a few minutes later ATC questioned if we were going to make it to 15 Miles South of ZZZ [VOR] at 8;000 feet. We advised that that was not our clearance and ATC issues the clearance of cross 15 miles south of ZZZ [VOR] at 8;000 feet; however; upon issue of said clearance we were already at 15 miles and at 9;000 feet; so we advised that we were unable. Of note; visibility was poor and ATC radio was highly congested with numerous VFR traffic.  I think our call sign just got confused with someone else. We did hear a (Company Flight ABC) also get a similar clearance before the confusion occurred.    I think the airspace was just too saturated and the congestion is what caused the mistakes.  We were never issued that clearance; nor did we ever read it back.
Air carrier flight crew reported ATC gave them a clearance meant for another company flight.