That's what youth can do. Teenagers start to grow up and are maturing so their mood swings can certainly show as they change. It's called 'hormones!' However, to ignore you or belittle you in any way is not acceptable and you have to learn NOW to stand on your own two feet and tell this person what they are doing wrong and ask them why they are behaving towards you in this manner. If they start to yell then walk away and drop this friend until they either apologize to you or if they don't keep walking. It hurts, but if you face a person and they make no attempt to rectify their behavior towards you then you have to learn to move on. You will come across this many times in your life.
Promises
Someone who always breaks promises could be described as untrustworthy, selfish, or two-faced.
an elephant is an elephant , an elephant never breaks its promises
Erosion
Weathering
Erosion
All warranties are different and carry different promises. One thing that a warranty often carries is that if the product breaks somehow, then they will replace the product or give you your money back.
erosion
Almost all acids will break down food. This is because many foods are very sensitive to their constantly changing environment.
Oxidation
If you are trained in changing your breaks or other automotive repairs you can change your breaks on your own. If this is not the case then it is best take your vehicle in to a mechanic.
Mechanical weathering.